Most students think getting a flu shot means they can count on being immune, but vaccine recipients are only 60 percent less likely to need treatment this season, according to the U.S. Department of Health and Human Services.

Flu vaccine effectiveness differs based on age and health status, said University Health Services nurse Charlotte Katzin

“Before administering shots, I don’t give students any specific percentage, or say ‘this is effective in this percentage of people,’ because that really varies,” Katzin said.

Each fall, a new strain of the flu spreads across the U.S. The Centers for Disease Control and Prevention are responsible for predicting which type of flu will be most prevalent each year, according to Dr. Elizabeth Loika, director of the Family Wellness Center.

“This year the CDC really got it right,” Loika said. “They pinpointed the right vaccine for the right strain much more accurately than ever before,” Loika said. “But, unfortunately, people do die from the flu.”

This season, 11 flu-related deaths have been reported in Travis County, including a child and a pregnant woman. Loika said preexisting health problems are usually a factor in the death of flu victims. Katzin said Texas is one of the few states where the flu is widespread.

College students may think they can stay healthy without a flu vaccine, but they are still at a high risk of exposure to the virus, according to Loika.

“When you have a basically healthy population, they don’t think flu shot down the road. … It’s probably the last thing on their minds,” Loika said. “But we recommend the flu shot particularly with college students because they’re all in class together, many times in a dormitory together, and there are lots of opportunities for the disease to spread.”

Electrical engineering sophomore Vyom Joshi said that, although he got his flu vaccine in October and assumed he was fully guarded from the illness, he still caught the virus.

“At least I didn’t have a severe case where I had to go to the hospital,” Joshi said.

Joshi said that, despite getting sick, he still would get the flu shot again next year.

“I think if you get a flu shot, the flu you get is at least milder than normal,” Joshi said.

Katzin said the efficacy of the shot decreases as the flu season progresses.

“We like to make sure that people understand — especially this time of year — the effectiveness might not be so great,” Katzin said.

It takes two weeks for the vaccine to develop protection, according to the CDC. If the flu is already circulating before someone gets the shot, that persons runs the risk of being exposed before building immunity to the virus, according to Katzin.

“Another thing we tell students is that it’s possible they could get exposed to a strain of flu that’s not in the vaccine,” Katzin said.

University Health Services has administered over 10,000 flu shots since September 2012 and received another 300 vaccine doses Wednesday because of high demand.